Air cooling apparatus



1938. J. R. BALLARD AIR COOLING APPARATUS 2 Sheets-Sheefl Filed July 5, 1934 IN VENTOR. J 0/-/ N 1?. BALLAR ATTORNEYS.

2 Sheets-Sheet 2 J. R. BALLARD AIR COOLING APPARATUS Filed Juiy 5, 1934 p s mm m A E4. w v; mm m k. W

Feb. 8, 1938.

Patented Feb. 8, 1938 UNITED STATES PATT OFFICE AIR COOLING APPARATUS Application July 5, 1934, Serial No. 733,742

12 Claims.. (01. 62-139) This invention relates to a method'of conditioning air and apparatus for carrying out the method.

One of the objects of the invention is the pro- 5 vision of improved apparatus adapted to cool and to circulate the air in a room and to effect a renewal of said air during the operation of the apparatus without materially changing the normal relative humidity of the air. Another object is the provision of such apparatus in which the cooling of the room air is effected by the evaporation of moisture by a portion of the room air. Another object is the provision of an air conditioning apparatus that is cheap to make, economical to operate and highly eflicient.

In the drawings, Fig. 1 represents a vertical sectional view of my apparatus with parts broken away to show certain constructional features.

Fig. 2 is a sectional view taken along the line 20 2-2 of Fig. 1, With certain parts broken away.

Fig. 3 is an enlarged fragmentary view looking down on the apparatus immediately below the top cover of the apparatus and adjacent one side thereof with certain parts broken away and in section for clarity.

Fig. 4 is an enlarged perspective view of one of the air cooling elements of my device.

Briefly described, my invention comprises what I term a dual system of air circulation. Re- 30 duced to its simplest form, the apparatus comprises a fan for circulating the air in a room and a thin sheet of metal is positioned relative to the fan so that the circulating air is drawn across one side of the sheet, which side is dry. The opposite side of the sheet is provided with a very thin moisture-absorbent surface, and means is provided to apply moisture thereto. A suction blower draws a portion of the room air over the wet side of the sheet, thereby promoting evaporation of the mois- 40 ture with a resultant cooling of the sheet, and the blower immediately ejects this wet air into the atmosphere outside the room.

In order to obtain the proper results, it is highly important that a relatively large volume per minute of room air be circulated across the cool dry. side of the sheet as compared to the volume per minute of air drawn across the wet side of the sheet. Otherwise the change of room air would be so rapid that the change in temperature caused to by passing the room air over the dry cold side of the sheet would be very slight. I have found that a ratio of about to l to be preferable, although fairly satisfactory results may be obtained from a ratio of about 5 to 1 to a ratio of to l.

55 It is also important that the moisture-absorbent surface of the sheet be very thin and that it is not maintained in an excessively wet condition so as to procure evaporation as close to the sheet as possible. This efiects a high efliciency in the transfer of heat. Preferably, the moisture is intermittently applied so as to not only tend to wash deposited solids from the moisture-absorbent surface, but also by permitting a certain amount of drying of the moist side of the sheet, there is a better cooling of the sheet. 10

In detail, my apparatus comprises a cabinet I, provided with legs 2 of any desirable length. Inside the cabinetin the lower portion thereof is a rectangular tank 3 provided with'a rectangular opening 4 in the top 5 thereof. Secured at its lower end within said opening 4 is a unit 6 made up of a horizontally extending row of connected, spaced, vertically disposed, parallel, rectangular, thin, copper plates 1. Every other pair of these plates is joined top and bottom by oppositely extending flanges 8 (Fig. 4) soldered together at adjacent edges or crimped together or secured together in overlapping relation as desired. The opposite vertical edges of adjacent plates of each of said pairs of plates are outwardly flanged at 9, best seen in Figs. 3 and 4, which flanges are curved transversely of their length in a manner to telescopically engage the flange of the adjacent plate so that a row of plates of any desired length may be quickly assembled.

Before assembling the pairs of plates, I cover the outer sides of each of the pairs of connected plates with a very thin sheet of high quality linen I, thus providing a moisture-absorbent surface on the outer sides of each of said pairs. Then when the pairs of plates are connected by telescopically engaging the flanges 9, it will be seen that a plurality of vertically extending passages is provided, having walls of moisture-absorbent material, and also a plurality of horizontally extending bare metal passages are provided by the adjacent inner sides of the moisture-absorbent walls.

At the opposite ends of a unit of plates, built up as above described, is a vertical end plate I of 4r relatively heavy material each extending at its opposite upper and lower ends above and below the plates 1. These end plates are secured respectively to the outer plate of the row of plates l by any suitable means, such as riveting or soldering.

Across the upper and lower ends of the flanges 9 are secured angle strips, the strips H at the lower ends respectively having one Of their legs extending vertically for securing to a vertically extending flanged edge of opening 4. The angle strip l2 extending across the forward upper edge of the row of plates 1 has a wide, vertically extending, leg that forms a battle plate across the forward upper corner of the unit of plates 1, and the rear strip l3 has its upwardly extending leg slanted forwardly over the upper ends of plates 1, best seen in Fig. 1, for a purpose later to be described.

Mounted on the top 5 of the tank and in front of the built up units of plates I, I provide. a pair of spaced fans l4 each with a small individual motor I5 connected to a suitable source of electrical power for rotating the fan'. As will be seen from Figs. 1 and 2, these fans are adapted to draw air through the horizontally extending bare metal passages provided between the pairs of plates 1, as already described, the rear wall of cabinet I being provided with a screen l6 for free entry of room air to the rear end of said passages.

Fans H are each rotatable in a ring I! formed in a housing l8. The housing [8 projects forwardly from the forward side of the unit 6, the rear upper and side edges of the housing connecting with the lateral and upper edges of the unit 6 and the lower side of the housing extending to the top 5 of the tank which mounts the motors I 5 and fans l4, said motors being supported on the tank top 5 by pedestal supports IS.

The front of cabinet I is provided with an adjustable grill 20 having generally horizontally extending, vertically spaced, blades 2| therein, these blades being slightly inclined upwardly from their rearto their forward edges so as to direct the flow of air slightly upwardly from the fans. the upper ends of its sides so that by pulling the lower endof the grill forward, the upward inclination of the plates is increased. Thus a greater upward throw is given to the air if desired. I find this system preferable to the ordinary system of introducing the circulating air at the top of the room, since the movement of air is more pronounced at about the height of a person in the room, where it is most needed.

Below the tank 3 is a suction blower 23 and electric motor 24 for operating the blower. The intake 25 of the blower is connected to a vertically extending, rectangular conduit 26 that extends upwardly through the bottom of tank 3 to adjacent the lower open ends of the vertical passages in unit 6, and across the open upper end of the conduit 26 is a horizontally extending, elongated, baffle plate 21 that extends across the greater length of the tank almost from end to end thereof, as best seen in Fig. 2.

Extending downwardly from the opposite longitudinally extending edges of the plate 21 are a pair of opposed plates '28 that are secured adjacent their lower edges to two opposite sides of the conduit 26! at the upper end of the conduit. Thus a sort of bonnet is secured over the upper open end of the conduit 26, and the lower edges of the plates 28 are inclined downwardly toward the upper end of the conduit to terniinate below the upper end of said conduit, whereby any moisture striking the bonnet will drain to below the open upper end of said conduit.

Connected to the suction blower discharge or outlet, is a discharge conduit or pipe 29 that extends vertically alongside the cabinet to about window height where it is directed horizontally outwardly through anelbow 30, which elbow is adjustable vertically on the vertical run 3| of the The grill is pivotally supported at 22 at discharge conduit. The outer end of the elbow 30 is adapted to extend through an opening 32 in a plate 33 that is adapted to fit between the lower edge of a room window 34 and the bottom of the window frame 35.

From the foregoing description, it will be seen that when the fans l4 and suction bl0wer'23 are operating, the room air is circulated again and again through the bare, horizontally extending passages in unit 6, while a portion of the room air is drawn through screen IS in the rear wall of cabinet I, downwardly through the vertical passages of unity 6 which are provided with moisture-absorbent surfaces I, and then through tank 3, conduit 26 and then this air'is ejected out of the room through conduit 30, 3|.

The fans I4 are of the type adapted to circulate a relatively large volume of air per minute as compared to the volume of air per minute drawn through the suction blower 23, hence the room air is re-circulated through the horizontally extending passages of unit 6 many times compared to the amount of air drawn through the vertically extending passages of said unit.

To provide for cooling plates 1, for taking up heat from the room air that circulates through the horizontal passages, I provide an automatically tilting V-shaped trough 36 extending centrally across the upper ends of plates 1, and which trough is pivoted at its ends at 31 in bearings in the upper ends of end plates II]. This trough is divided centrally by a plate 38, thus in reality providing two adjacent V-shaped troughs 36a and 36b and the pivots are adjacent the apex at the bottom of the troughs at opposite ends thereof, end plates 39 being provided at opposite ends of trough 36.

A small rotary water pump 4!] inside the tank 3 adjacent the bottom thereof actuated by a small electric motor 4| is adapted to pump water from the tank 3 through a a vertically extending pipe 42 into the trough 36.

As will be seen from Fig. 1, the outlet pipe 42 is vertically above pivot 31 and when the side 1 bend the outer edges of said troughs back as at I 43 and at the bends provide a row of small openings 44, one opening over the linen covered connecting flanges 8 at the top of each of the pairs of plates 1, so that when the trough 36 is tipped, there is first a sudden splash of water over the edge and then the water remaining in whichever of troughs 36a or 361) is lowermost, is gradually drained out of openings 44 directly onto the linen covered upper connecting flanges 8 of plates 1 and is spread by absorption over the sides of the plates.

By the foregoing construction, it is seen that the air drawn through the vertical passages in unit 6 effects an evaporation of the moisture on the sides of the vertical passages, with the result that the dry horizontal passages through which the greater portion of the room air is circulated, is cooled. The heat of the room air is thus taken up by the cool dry sides of the horizontal passages and is transferred to the moisture-laden 7 air passing out of the room through the suction blower. The air thus removed is replaced by the ordinary leakage through the doors and wincomplish the result of creating a continuous eddying efiect upon the air passing therethrough so that all of the air passing through said passages is circulated against the walls of the passages many times before it is ejected back into v,

the room. I have experimented with square flanges, tapered flanges and other shaped flanges at the entering ends of said horizontal passages, but in any shape other than that adopted, the resistance to the passage of the air is too great, or else there is a reduction in the eddying of the air currents and a lesser degree of cooling thereof, since the air comes in contact with the walls to a lesser degree. The fan motors it are also of variable speed type so that a larger or smaller volume of air can be circulated as desired.

In previous air conditioners, where a continuously flowing stream of water is used to moisten a moisture-absorbent surface, I have found that there is a reduction in the cooling resulting from the evaporation of the moisture, and while any excess moisture in my device drains back into tank i, there is very little of such excess, since between tiltings of the trough 36, there is a period of drying and by the time the moisture reaches the bottom of unit 8, the upper portion of half of the unit is capable of taking up moisture from the next tilting of the trough, hence the flow from each successive tilting of the trough is reduced. This alternate drying and moistening results in bringing the evaporating surface ofthe water appreciably closer to the plates l than would otherwise result. By using'thin copper plates and a very thin moisture-absorbent surface, the evaporation actually occurs practically on the plate itself, and there is no loss in heat transfer,

In actual practice in normal temperate climates where the relative humidity is about from to with my apparatus and method as described, I accomplish a reduction in the temperature of the air of an ordinary sized room from about 90 to about to 78 and where the relative humidity is lower, there is a much greater reduction since evaporation is much fas- It is, of course, obvious that in winter time, when an increase in the relative humidity of the air in a room is desirable, I may accomplish this result by merely providing a damper in the conduit that normally discharges air out of the room, and direct the air into the room instead, or else provide a return bend or elbow 3t and direct the air through the horizontal passages in unit 6 back into the room.

Various means might be provided for maintaining the water level in tank 3 so as not to overflow into conduit 26'. In the drawings I merely show a filling funnel 55 on the rear of the tank, and when the water rises in the funnel, to about the top thereof, the operator knows that the tank is properly filled and stops filling before the, funnel overflows. Also a sight gage d6 having a float 41 that rises and falls with water level 58 is observable through the fan opening.

The air-circulating unit of my device, including the fans, blower, tank, unit 6, etc., are all removable as a unit from the cabinet I upon removing the rear panel of the cabinet, said assemblage being supported on strips 49 on the inner opposite sides of the cabinet.

Having described my invention, I claim 1. Apparatus for cooling the air of a room comprising a horizontally extending row of openended tubular members of relatively thin sheet metal arranged to provide a. plurality of horizontally extending passages therethrough, means arranged and adapted to connect and space the tubular members of the row one from the other, thereby providing a plurality of vertically extending passages therebetween, the outer sides of said tubular members being provided with a thin water-absorbent material, means for supplying water to said material including a tank positioned below the tubular members arranged and adapted to receive excess water from the moisture-absorbent material, means for circulating the air of the room through the horizontally .extending passages and means for drawing air through said moistened vertical passages including a conduit having a suction inlet positioned within said tank above the water level and an outlet arranged to discharge the air out of the room, and a suction blower interposed in the conduit for drawing the air therethrough and ejecting it out of the room.

2. Apparatus for cooling the air of a. room comprisinga horizontally extending row of openended tubular members of relatively thin sheet metal arranged to provide a plurality of horizontally extending passages therethrough, means arranged and adapted to connect and space the tubular members of the row one from the other, thereby providing a plurality of vertically extending passages therebetween,- the outer sides of said tubular members being provided with a moisture-absorbent surface, means arranged and adapted to intermittently discharge water to the outer sides of each of said tubular members at predetermined uniformly spaced intervals of time for supplying moisture to the moistureabsorbent surface, means for circulating the air of the room through said horizontally extending passages and means for drawing a relatively small portion of the room air through said vertically extending passages and to eject said portion to the outside of the room.

3. Apparatus for cooling the air of a room comprising a horizontally extending row of flat-sided, open-ended tubular members of relatively thin metal arranged in a row with their flat sides parallel, means connecting the members of the row adjacent their opposite open ends adapted to space said members thereby providing a plurality of fiat-sided vertically extending passages between adjacent outer sides of said members, means for drawing room air through said hori-. zontally extending passages and separate means arranged and adapted to draw a portion of the. room air through said vertically extending passages and to eject said portion of the room air to outside the room, means arranged and adapted to supply moisture to the surface of the walls forming the vertically extending passages, the means connecting said tubular members comprising flanges extending oppositely outwardly from opposite lateral edges of the ends of said tubular members, the flanges on one side of each 75 the open ends of the horizontally extending passages for facilitating the circulation of air therethrough.

4. Apparatus for cooling the air of a room comprising a horizontally extending row of flat-sided, open-ended tubular members of relatively thin metal arranged in a row with their flat sides parallel, means connecting the members of the row adjacent their opposite Open ends adapted to space saidmembers thereby providing a plurality of flat-sided vertically extending passages between adjacent outer sides of said members, means for drawing room air through said horizontally extending passages and separate meansarranged and adapted to draw a portion of the room air through said verticallyextending passages and to eject said portion of the room air to outside the room, means arranged and adapted tosupply moisture to the surface of the walls forming the vertically extending passages comprising an elongated receptacle for a liquid extending transversely of said tubular members across the upper sides thereof, means pivoting said receptacle for oscillation on its longitudinalaxis whereby liquid contained therein will be alternately discharged on opposite sides thereof upon oscillation thereof to flow down the walls of the vertically extending passages, means for supplying liquid to said receptacle and said receptacle being formed to oscillate automatically for automatically discharging the liquid upon the liquid filling the same.

5. In an air-cooling device a casing, a plurality of straight, horizontally extending open-ended tubular members therein spaced apart forming vertically extending open-ended passageways therebetween, the walls of which are defined by the outer sides of said tubular members, power actuated suction means positioned over one end of the tubular members adapted to draw air through said tubular members and to eject said air into the room, said casing being provided ,with a horizontally directed opening disposed over substantially the full horizontally projected area of the opposite ends of the plurality of tubular members whereby the air in the room will be simultaneously admitted directly from the room into the open ends of said tubular members for passage therethrough upon actuation of said suction means, means for moistening the outer sides of said tubular members and suction means for drawing a portion of the room air through said vertically extending passageways for evaporating the moisture on the walls thereof.

6. In a construction as defined in claim 5,.

means arranged and adapted to conduct said portion of the room air from said last mentioned suction means to outside the room.

7. In apparatus for cooling the air of a room, means forming a plurality of horizontally extending open-ended air passageways and a plurality of vertically extending open-ended air passageways comprising a row of spaced rectangular flat plates of thin sheet metal disposed generally vertical with their flat sides substantially parallel, the alternate plates of the row being formed with flanges along their opposite lateral edges extending in the same direction and said alternate plates being formed with flanges along their upper and lower edges extending in a direction opposite to the direction of the flanges along the lateral edges, said flanges along the lateral and upper and lower edges of the alternate plates being secured to the plates adjacent thereto whereby the flanges along the lateral edges of the plates and the flanges along the upper and lower edges of the plates form opposite sides of the vertically and horizontally extending passageways respectively, separate means'arran'ged and adapted to draw room air through the horizontally and vertically extending passageways respectively and means for supplying moisture to the sides of the vertically extending passageways.

8. Apparatus for cooling the air of a room comprising a plurality of flat-sided open-ended tubular members arranged in a row with their flat sides in-opposed relation, a'sheet of thin, absorbent material covering the outer sides of said tubular members, means for supplying moisture to the absorbent material, means for drawing room air through said tubular members and for ejecting said air back into the room, means for drawing a portion of the room air between adjacent outer sides of said tubular members and for ejecting said portion of room air to outside the room, the outer flat sides of said tubular members being disposed relatively close together and spaced a distance less than the distance between the opposed inner flat sides of the tubular members.

9. Apparatus for cooling the air of a room comprising a casing, an open-ended tubular member therein having relatively thin and relatively wide vertically extending side walls positioned close together, means forintermittently supplying moisture to the opposite outer surfaces of the walls of said tubular member, means for moving room air through said tubular member and. back into the room, means for moving air over the outer moistened surfaces of the walls of said tubular member and for ejecting said last mentioned air to outside the room, the bore of said tubular member being substantially straight and of substantially uniform cross sectional area from end to end.

'10. The method of conditioning the air of a room that comprises moving a relatively large volume, per minute, of the air of the room in contact with one side of a plurality of heat ex-" change surfaces and back into the room for repassage in contact with said surfaces while moving an appreciably smaller volume, per minute, of the air of the room across the other side of said surfaces and to outside the room, periodically moistening said other surfaces at intervals of time duration sufilcient to effect relatively complete evaporation of the moisture on said other surfaces by the air moved thereacross between each of the moistenings whereby the evaporation of the moisture at said other surfaces will effect a progressively increased cooling of the heat exchange surfaces following each moistening of said other surfaces and the room-air moved in contact with the first mentioned side of the heat exchange surfaces will be cooled.

11. The method of conditioning the' air of a room .that comprises moving a relatively large volume, per minute, of the air of the room in con-.

tact with one side of a plurality of heat exchange surfaces and back into the room for re-passage in contact with said surfaces while moving an appreciably smaller volume, per minute, of the air of the room across the other side of said surfaces and to outside the room, and periodically moistening said other surfaces with a relatively thin sheet of moisture whereby the air moved across the moistened surfaces will cause evapora- II tion of the moisture to thereby effect a cooling of the first mentioned side of the heat exchange surfaces for cooling the room-air moved in contact therewith and back into the room.

12. The method of conditioning the air of a room that comprises simultaneously moving air of the room in contact with one side of a plurality of heat exchange surfaces and over the other side of said surfaces in the rates of from about five to fifteen times more air being moved in contact with the first mentioned side of the heat exchange surfaces, periodically moistening said other surfaces with a relatively thin sheet of moisture, ejecting from the room the air moved over said other surfaces while ejecting the air moved in contact with the first mentioned side of the surfaces back into the room for r'e-passage in contact with the first mentioned side of the surfaces and for movement with the room-air over said other surfaces inaforesaid ratio.

JOHN R. BALLARD. 

